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How can I SELECT rows with MAX(Column value), DISTINCT by another column in SQL?
...en home. Reason being GROUP BY will fetch any random row for each home and ORDER BY will just sort the overall all result as produced by GROUP BY
– sactiw
Nov 26 '15 at 12:11
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The type must be a reference type in order to use it as parameter 'T' in the generic type or method
...koverflow.com%2fquestions%2f6451120%2fthe-type-must-be-a-reference-type-in-order-to-use-it-as-parameter-t-in-the-gen%23new-answer', 'question_page');
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Can I set up HTML/Email Templates with ASP.NET?
...fit of this approach is consistency. For example, you could show a user an order summary and include exactly the same thing in the confirmation email by reusing the same control.
– Mun
Mar 26 '09 at 21:19
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Using helpers in model: how do I include helper dependencies?
...
To access helpers from your own controllers, just use:
OrdersController.helpers.order_number(@order)
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What does SQL clause “GROUP BY 1” mean?
...the first column regardless of what it's called. You can do the same with ORDER BY.
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Which method performs better: .Any() vs .Count() > 0?
...etter than Count() > 0 - I've had situation in which Count is faster by order of magnitude on SQL Server (EntityFramework 4).
Here is query with Any that thew timeout exception (on ~200.000 records):
con = db.Contacts.
Where(a => a.CompanyId == companyId && a.ContactStatusId <...
Remove duplicate rows in MySQL
...owing columns:
employee (id, first_name, last_name, start_date, ssn)
In order to delete the rows with a duplicate ssn column, and keeping only the first entry found, the following process can be followed:
-- create a new tmp_eployee table
CREATE TABLE tmp_employee LIKE employee;
-- add a unique...
How do I delete a fixed number of rows with sorting in PostgreSQL?
...DELETE FROM logtable
WHERE ctid IN (
SELECT ctid
FROM logtable
ORDER BY timestamp
LIMIT 10
)
The ctid is:
The physical location of the row version within its table. Note that although the ctid can be used to locate the row version very quickly, a row's ctid will change if it is...
What are good examples of genetic algorithms/genetic programming solutions? [closed]
...nute-by-minute price data of the S&P500 futures, as well as a specific order (buy or sell) and stop-loss and stop-profit amounts. Each string (or "gene") had its profit performance evaluated by a run through 3 years of historical data; whenever the specified "shape" matched the historical data,...
Condition within JOIN or WHERE
...sider these two queries:
SELECT *
FROM dbo.Customers AS CUS
LEFT JOIN dbo.Orders AS ORD
ON CUS.CustomerID = ORD.CustomerID
WHERE ORD.OrderDate >'20090515'
SELECT *
FROM dbo.Customers AS CUS
LEFT JOIN dbo.Orders AS ORD
ON CUS.CustomerID = ORD.CustomerID
AND ORD.OrderDate >'20090515'
The f...